Explanations and comparisons

Reminders

  • Workbook homework due on Thursday

Goals

  • Begin looking at relationships between variables

  • Theoretical Arguments and Hypotheses

  • Elements of a good theory

  • Writing good hypotheses

  • Testing Hypotheses

The goals of research

  • Describing: making generalization about the world

  • Predicting: generating expectations about what will happen in the future

  • Explaining: explaining why things are related.

Explanation is often the toughest to achieve, but also the most desirable because it allows us to do things like make changes to reach a desired outcome.

“Why” questions

  • “Why questions”

    • Why do some eligible voters fail to turn out on election day?
    • What explains variation in gun policies across U.S. states?
    • Why did communist revolutions happen in China and Russia but not Europe or the United States?

Theories

“a logically interconnected set of propositions from which empirical uniformities can be derived” – Robert K Merton

Theories are explanations, assumptions, claims and narratives that provide a set of expectations that link a cause to an effect.

Purely descriptive or predictive analyses don’t necessarily require a theory, but its a key component of explanatory research.

Assessing Theories

  • Theories require simplified representations of a complex reality

  • Utility, not “truth”: theoretical models invariably contain assumptions and they’re probably violated in practice.

George Box: “All models are wrong, but some are useful”

Theoretical Scope

Theories vary in their scope:

  • Early sociologists like Marx, Durkheim, Weber attempted to develop all-encompassing “laws” of political/social/historical change. These are sometimes called “grand theories”
  • Contemporary social sciences are less ambitious, and so its more common to propose “middle-range” theories that seek to explain a smaller number regularities in one area.
    • However, they may draw on “grand theories” either implicitly or explicitly.

Grand theories: Paths to Modernity

What explains differences in the “path to modernity” across different countries during the 20th century?

  • Free markets/Democracy in the U.S. and England

  • Fascism in Germany and Japan

  • Communism in Russia and China

Grand theories: Paths to Modernity

Barrington Moore: Classes have unique and conflicting interests. Conflicts over these interests come to the forefront during industrialization. The outcomes of these class conflicts shape the political and economic system.

Grand theories: Paths to Modernity

  • Fascist states emerge when the landed aristocracy allies with industry to repress the peasantry.

  • Communist states emerge when the middle class doesn’t emerge and peasants revolt.

  • Democracies emerge when the bourgeoisie (middle class) is strong.

Grand theories: Paths to Modernity

  • Moore’s theory borrows assumptions from a (sociological) Marxist grand theory about class conflict

  • He “tests” it by showing how it fits the selected cases.

Grand theories: Paths to Modernity

Good theories can be used and refined to generate a set of empirical expectations about what factors should matter. For instance, we might expect:

  • States with larger agricultural sectors during industrialization to be less democratic today (compared to states with smaller agricultural sectors)

  • States with higher literacy rates during industrialization to be more democratic (compared to states with lower literacy rates)

Good Theories

  • Good theories clearly identify:

    • A dependent variable(s): the outcome to be explained

    • One or more independent variables: the causal factors that determine the DV.

    • A causal mechanism that links these two things.

    • An expectation about the direction of the effect (positive, negative, something more complex)

Good theories

  • Most social science theories are probabilistic instead of deterministic. So we’ll speak in terms of more/less likely or higher/lower.

  • Good theories should generate expectations that can be empirically tested (even if the theory itself can’t be tested)

Causal diagrams

  • Causal diagrams are a way to visualize cause and effect relationships in a theoretical model.

G Cause Cause Outcome Outcome Cause->Outcome

Causal diagrams

  • Nodes indicate variables, and arrows indicate causal relationships.

G Cause Cause Outcome Outcome Cause->Outcome

Causal diagrams

For instance, we might think about a simplified version of Moore’s thesis like this

G Cause Strength of the middle class Outcome Democracy Cause->Outcome

Causal diagrams: forks

A “fork” refers to a case where a single cause leads to multiple outcomes of interest.

G Cause Strength of the middle class Outcome Democracy Cause->Outcome Outcome2 Wealth Cause->Outcome2

Causal diagrams: collisions

A “collision” happens when two causes “collide” on a single outcome:

G Cause Strength of the middle class Outcome Democracy Cause->Outcome Cause2 Culture Cause2->Outcome

Causal diagrams: chains

A chain refers to a scenario where one outcome causes something else, which influences a third thing.

G Cause1 Natural resources Cause Strength of the middle class Cause1->Cause Outcome Democracy Cause->Outcome

Causal diagrams

  • In practice, causal diagrams will usually be a lot more complicated than this, but the end goal is systematically identify testable claims about some outcome.

From Vincent Arel-Bundock

Theories: voting

Why do people vote?

  • Since politicians generally offer public goods, you can enjoy the benefits of your preferred candidate winning even if you don’t vote

  • Since voting has costs (even though they’re small) free riding can be preferable to actually turning out if the costs outweigh the benefits.

Theories: voting

Pivotal voting

Claim: people vote because they expect to sway the election

If this is true, then:

  • Turnout should be higher in close elections
  • Turnout should be higher when the electorate is small
  • Turnout will be higher in PR systems where one vote matters more.

Theories: voting

Expressive voting model

Claim: people vote to enjoy the expressive benefits

If this is true then:

  • People with more extreme beliefs will be more likely to vote
  • Closeness or the size of the electorate shouldn’t matter much

Assessing Theories

Consistency

  • Is our theory internally consistent?
  • Does it have a clear logic?

Assessing Theories

Empirical accuracy

  • Do the theories help us understand the world?
  • Are observed realities consistent with the expectations our theory generates?
  • Can we use a theory to make useful predictions about future events?
  • Can the theory adapt in the face of inconsistent findings? (this will happen!)

Hypotheses

  • Theories give causal explanations for why something effects something else

  • Hypotheses are specific testable implications generated by that theory.

    • Theory: people vote because of expressive benefits

    • Hypothesis: people with more extreme views will be more likely to turn out.

Hypotheses

Components:

  • Unit of analysis

  • Dependent variable

  • Independent variable

  • Direction of the predicted relationship

Good hypotheses inevitably involve comparative language (higher/lower/more/less/increase/decrease/better/worse)

Hypothesis Template

In a comparison of [unit of analysis], those having [one value on the independent variable] will be [more/less] likely to have [one value on the dependent variable] than those having a [different value on the independent variable].

Hypothesis Template

In a comparison of [voters], those having [stronger political views] will be more likely to have [a higher likelihood of turnout] than those having a [weaker views].

  • Unit of analysis: voters

  • IV: strength of political views

  • DV: turnout

  • Relationship: strength increases turnout

Hypothesis Template

In a comparison of [states], those having [a larger middle class during industrialization] will be more likely to have [democracy] than those having a [a smaller middle class].

  • Unit of analysis: states

  • IV: size of the middle class

  • DV: democracy

  • Relationship: middle class increases likelihood of democracy

Hypothesis Template

In a comparison of [survey respondents], those having [higher levels of attention to politics] will be more likely to have [consistent responses] than those having a [lower levels of attention to politics].

  • Unit of analysis: Survey respondents

  • IV: level of attention

  • DV: response consistency

  • Relationship: attention increases consistency

Complex Relationships

Good hypotheses may suggest a more complex set of relationships than just “positive/negative”. They could propose conditional/interactive/curvilinear relationships as well.

The “oil curse”

In a comparison of [countries], those having [higher levels of GDP] will be [more likely to be democratic] compared to [countries with lower GDP], [however, this relationship will not hold for countries that get rich from oil exports.]

Retrospective voting:

In a comparison of [voters], those having [lower levels of attention to politics] will be [more likely to vote for the incumbent when the economy is doing well]. Those having [higher levels of attention to politics] will be [more likely to vote based on policy preferences regardless of the state of the economy]

Bad hypotheses

  • The main determinant of war is the distribution of power in the international system.

  • In comparing individuals, annual income and the level of education are related.

  • Democracies are peaceful. In comparing individuals, some people are more likely to favor the death penalty than others.

Next

  • Testing hypotheses by making comparisons

  • Graphing and describing relationships